1. Field of the Invention
The present invention relates to a communication system in which a communication apparatus can establish one-to-one wireless link with another communication apparatus by being disposed close within a predetermined range to perform data communication.
2. Description of the Related Art
In recent years, mobile telephones with a short-range data communication function using an infrared ray called an Infrared Data Association (IrDA) have appeared in the market, and various services using the IrDA have begun to spread out. By using the IrDA, transmission and reception of data such as image data and addresses between two sets of mobile telephones can be carried out as discussed in US 2007/0190936.
A general data communication method in mobile telephones with the IrDA will be described below. Firstly, a user “A” at a data transmission side operates a mobile telephone “a” and selects transmission target data, and activates a transmission application. Then, a user “B” at a reception side operates a mobile telephone “b” and activates a reception application, whereby data is transmitted from the mobile telephone “A” to the mobile telephone “B”.
Further, recently non-contact communications (short-range wireless communications) such as Near Field Communication (NFC), TransferJet (trademark) have appeared. These non-contact communications, with very short communication distance, are controlled so that, when apparatuses that perform communications are brought as near as several centimeters or less to each other (for example, 10 cm or less for the NFC, 3 cm or less for the TransferJet), the wireless link is connected, and when they are moved away from each other, the wireless link is disconnected.
In the TransferJet, it is assumed that apparatuses perform one-to-one data communication with each other, and now a white paper describing use a case or the like is open to public view (Non-Patent Document 1:
http://www.transferjet.org/tj/transferjet_whitepaper.pdf. In the Non-Patent Document 1, with the TransferJet, apparatuses are disposed very near to each other whereby enabling users to perform sharing of data.
In the case of the data communication method by the above-described IrDA, users of mobile telephones determine transmission side/reception side by verbal exchange of talks, and each is to activate transmission or reception application. Therefore, if the mobile telephones “a” and “b” each have data for transmission target, the user “A” and the user “B” must interchange roles of the transmission and reception, and perform again the above-described operation. If the transmission application is activated by both mobile telephones due to the user's mis-operation or lack of communication, the data communication cannot be carried out.
Also, as a method for data sharing in the TransferJet, such a method may be possible, in which the data communication is performed by bringing the user's own apparatus very close to another apparatus (partner apparatus), after the user has performed operation such as selection of transmission data. This is because, in the non-contact communications, if a distance between the apparatuses becomes a little far, outside the communication range, the wireless link will be eventually disconnected, accordingly it is difficult to perform operation such as selection of transmission of data, while keeping to maintain connection of the wireless link. However, how to control the data transmission and reception if the both apparatuses are brought close to each other in a state where selection of transmission data or the like is performed by the apparatuses, is not discussed in the Non-Patent Document 1.